It is known, as in U.S. Pat. No. 4,165,825, for example, to provide a valve for a pressurized container with a flow control or locking member which is mounted on the outer periphery of a valve stem with screw threads. The flow control member in this known device is provided with a pair of opposed outwardly extending finger-engaging flanges to assist in rotating the flow control member. When such flow control member is screwed downwardly toward the adjacent container, the lower end of a downwardly and outwardly flaring skirt of the flow control member engages the end wall of the mounted valve cup and prevents actuation of the valve. For dispensing material, the flow control member is screwed upwardly a desired distance to permit the valve stem to be depressed and hence opened a selected amount. The flow rate of material dispensed is a function of the height of the flow control member since this determines the extent of possible opening of the valve. In particular, when the flow control member is moved upwardly only a short distance and the valve is then depressed, either vertically or by tilting, the edge of the skirt of the flow control member engages the end wall of the valve cup after the valve has been unseated and moved only a small distance so that the material is slowly dispensed. If the flow control member is rotated to a location relatively higher on the stem of the valve, the opening between the valve stem and its associated seat is increased and accordingly the flow rate of the material being dispensed is increased. This type of flow control member is desirable because it enables the user to accurately control the rate at which material is being dispensed such as when dispensing a caulking compound or the like, to allow the user to form a perfect bead of material along the joint being caulked.
This known flow control apparatus is illustrated in FIGS. 1 and 2 of the drawings wherein it is seen that the flow control or locking member 1 is mounted by rotation by cooperating screw threads 2 on valve stem 3 of a valve 4. The valve is secured in the end wall 5 of a container 6 with a resilient grommet 7 for dispensing pressurized material such as caulking or the like from the container. The flow control member includes a skirt 8 for engaging the end wall 5 and finger-engaging flanges 9.
In this known flow control arrangement, both the valve and the flow, control member are manipulated by the fingers of the user. This can be tedious and may require tilting the valve in a way in which renders it more difficult to apply the dispensed material from the dispensing tip 10 as shown in FIGS. 1 and 2.
In another known flow control apparatus, a wire control handle is mounted at the end of the container adjacent the flow control member. This apparatus is shown in FIGS. 3, 4 and 5 wherein the wire control handle is designated 11. The free ends 12 and 13 of the wire of the control handle at one end of the handle are pivotably mounted in openings of a stationary bracket 14 rigidly secured to the upper end of the container. The bracket is fixed in position on the end of the container and is relatively larger in diameter than the diameter of the container such that the bracket can interfere with or make it more difficult to rotate the flow control member with the fingers and to use the container during dispensing in confined areas. The fingers can also be caught and possibly injured on the mounting bracket. The other end of the control handle is adapted to be pressed by the user to depress the flow control member and valve by a second class lever action during dispensing. Rotation of the flow control member upwardly causes the end of handle to pivot outwardly from the container to permit such dispensing at a flow rate which is a function of the adjusted height of the flow control member. The valve stem on this known flow control arrangement has a flat machined on either side of the stem thereby reducing peripheral thread engagement to approximately 60%. This causes the flow control to "slip" or "jump" threads when vertical pressure is applied.